CVE-2023-4105 : What You Need to Know

This CVE-2023-4105 was assigned by Mattermost and published on August 11, 2023. It pertains to a vulnerability in Mattermost that allows a simple user to access and download attachments of deleted messages in a thread.

Understanding CVE-2023-4105

This vulnerability in Mattermost poses a risk to the confidentiality of data as it fails to delete attachments when deleting a message in a thread. This oversight enables unauthorized users to still access and download the attachments of deleted messages.

What is CVE-2023-4105?

The CVE-2023-4105 vulnerability in Mattermost stems from the platform's inability to thoroughly delete attachments when a message is deleted in a conversation thread. This flaw allows ordinary users to retrieve and download attachments from deleted messages, potentially leading to unauthorized access to sensitive information.

The Impact of CVE-2023-4105

With a CVSS v3.1 base score of 3.1, CVE-2023-4105's impact is considered low severity. However, the vulnerability's high attack complexity and network-based attack vector make it critical as it compromises data confidentiality, allowing unauthorized users to retrieve attachments from deleted messages.

Technical Details of CVE-2023-4105

This vulnerability is classified under CWE-862: Missing Authorization, highlighting the authorization gap that enables users to access deleted message attachments. The affected versions of Mattermost include 7.8.7, 7.9.5, and 7.10.3, while versions 7.8.8, 7.9.6, and 7.10.4 are unaffected.

Vulnerability Description

Mattermost's failure to completely delete attachments when deleting messages in a thread allows unauthorized users to access and download the attachments of deleted messages, compromising data security.

Affected Systems and Versions

Mattermost versions 7.8.7, 7.9.5, and 7.10.3 are affected by this vulnerability, while versions 7.8.8, 7.9.6, and 7.10.4 remain unaffected.

Exploitation Mechanism

This vulnerability can be exploited by a simple user within the system to retrieve and download attachments from messages that have been deleted within a conversation thread.

Mitigation and Prevention

To address CVE-2023-4105 and enhance the security of Mattermost servers, immediate steps need to be taken along with the implementation of long-term security practices.

Immediate Steps to Take

Users are advised to update their Mattermost servers to versions 7.10.4, 7.9.6, 7.8.8, or higher to mitigate the vulnerability and prevent unauthorized access to deleted message attachments.

Long-Term Security Practices

Regular security audits, access control reviews, and employee training on secure data handling are essential for maintaining data confidentiality and preventing unauthorized access to sensitive information.

Patching and Updates

Regularly applying security patches and updates provided by Mattermost is crucial in mitigating vulnerabilities like CVE-2023-4105 and ensuring the overall security of the messaging platform.